We were surprised to discover that the weight difference between X0 and X9 is down to the shifter covers. What’s more shocking, on SRAM’s flagship units, is that the left-hand shifter cover is a loose fit. We checked other X0 units on test bikes in our workshop and found them to be the same. It is almost as if the wing-nut holding the cover in place needs an O-ring to preload it and stop it rattling.

Shifting is crisp and precise and the adjustable aluminium upshift paddle allows you to fine tune the position. Lever finish is better than X9 but if you are wearing full finger gloves you will not notice any difference. If you want the best Sram shifter then it has got to be X0 — however you end-up paying a high price for a small gain over X9.

Mbr rating: 8